In this project, immunolgical reactivity of cancer patients will be studied before treatment and during chemotherapy and immunotherapy. The objective of the study will be to establish the relationship between immunocompetence and prognosis and to accurately evaluate the immunological effects of chemotherapy and immunotherapy. The least immunosuppressive chemotherapy and the most immunopotentiating immunotherapy will be sought. The immunological tests to be evaluated will include skin tests with recall antigens, a lymphokine skin test, and a variety of studies of cell-mediated immunity studies in vitro, including the following: tests of macrophage function including C14 glucosamine incorporation, phagocytosis and macrophage cytotoxicity, lymphocyte cytotoxicity induced by allogeneic stimulation, and antibody-dependent cell-mediated cytotoxicity. The disease categories to be studied will include melanoma stage III and IV, breast cancer, stage IV, lung cancer stages I-IV, and leukemia. Immunotherapies to be studied include BCG, C. parvum and MER. The potential benefit will be improved prognostication for the cancer patient and the selection of better therapies.